A malicious website may be presented in various forms, such as a phishing website and a web page virus. The web page virus is a virus that causes damage through a web page. The web page virus exists in a web page and uses malicious codes written in certain program languages to embed a virus due to software vulnerability. When a user logs on to or visits some websites containing web page viruses, the web page viruses are activated secretly. Once activated, these viruses can use resources of a system of a terminal to cause harm to the system. At best, a user's information may be modified, titles of a home page and a browser of the user may be changed; at worst, many functions of a system can be closed, the Trojan horse is installed, and a virus is embedded, thereby adversely affecting the normal function a computer system. In a severe situation, the computer system can be re-formatted. Moreover, such a web page virus can be easily written and revised. Therefore, it is very difficult for a user to track the web page virus and guard against the web page virus.